Clutch control mechanisms



Jluly 6, 1937. E. G; HILL ET AL. 2,086,501

CLUTCH CONTROL MECHANISMS Filed Aug. l0, 1954 3 Sheets-Sheet l 3 rvu cmi/0430 July 6, 1937. E. G; HILL. ET AL 2,086,501

CLUTCH CONTROL MECHANISMS Filed Aug. l0, 1934 5 Sheets-Sheet 3 3x1/umm [ow/wa 6TH/1 1. HIS/Wy WHEY @RQA Patentedv July 6, 1937 PATENT ori-ice CLUTCH CoNmoL Mechanisms Edward G. Hilf, South Bend, Ind., zm Henry W. Hey, Richmond, Va., assignors to Hill Engiv neering Corporation, Richmond, Va., a. corpora tion of Virginia Application August 1l),

23 Claims.

This invention relates to clutch control mechanisms for motor vehicles.

Many eiorts have been made during the past few years to provide an eicient mechanism for automatically controlling the operation of a motor vehicle clutch,`partic1'11ar1y in conjunction with the manual operation of the engine throttle. lractically all of the development work along this line, so far as we are aware, has been done lo in connection with the control valve or valves motor vehicle clutch. The present invention,

thereforefcontemplates no improvement over the operating valve mechanism per se, but provides improved means for controlling the operation of 25 such valve mechanism. Y

' An important object of the present invention is to provide a novel control mechanism for the engine throttle and the clutch control valve mechanism, operated from the accelerator pedal of the vehicle. l,

y More specifically, an important object of the invention is to provide operating means of the character referred to which functions to .provide a relatively rapid releasing of the clutch elements for movement toward operative engagement and then checking the movement of such elements prior to any substantial opening movementof the engine throttle whereby relatively rapid elutchengagement is permitted to take place. A further object is to provide operating means "of the character referred to which functions to provide initial operation of the clutch control valve mechanism at a relatively faster rate than the opening movement of the throttle, from the idling position of the latter, and upon further opening movement of the throttle, to provide .faster movement of the throttle than of the control valve mechanism,A thus providing the two results of `permitting the clutch to move rapidly 5@ to the point where its movement is checked, and

then to provide relatively slower controlled movement of the clutch elements upon increased engine speeds whereby smooth clutch engagement is obtained.

Conversely, an important object of the inven- 1934, serial'No. '139,313

tion is to provide relatively faster movement of the control valve mechanism than of the throttle as the latter approaches idling position upon the releasing of the accelerator to thereby effect extremely rapid disengagement of the clutchupon the releasing of the accelerator pedal to prevent the transmission of motor drag to the vehicle when the clutch is released.

A further object is to provide a device of the character referred to wherein the travel of the clutch control valves is substantially shortened, thus permitting the use of a. smaller valve mechanism with a consequent reduction in the cost of manufacture of such mechanism.

A further object is to provide means operable when the accelerator is suddenly released for slightly retarding the return movement of the throttle to idling position without affecting the operation of the control valve mechanism, thus providing a rapid releasing of the clutch elements to prevent the transmission of motor drag to the vehicle. A

A further vobject is to provide means automatically operable upon the rapid depression of the accelerator pedal from idling position for Changing the ratio of movement between the control valve mechanism and the throttle whereby the latter operates relatively. more rapidly 'with respect to the control valve mechanism to provide a relatively fast clutch engagement.

A further object is to provide lever means for transmitting movement from the accelerator pedal to the throttle and to the control valve mechanism and wherein the effective lever lengths controlling the movement of the throttle and control valve mechanisms are altered under diierent operating conditions to provide the foregoing results.

Other objects and advantages of the invention will become apparent during the course or" the following description.

In the drawings we have shown several embodiments of the invention. In this showing:

Figure 1 is a side elevation of a motor vehicle power plant showing the invention applied, a portion of the vehicle being shown in section,

Figure 2 is a central longitudinal sectional view through the control valve mechanism,

Figure 3 is a section on line 3-3 Vof Figure 2,

Figure 4 is an enlarged side elevation of the control levers and associated parts,

Figure 5 is an edge elevation of the same,

.Figure 6 is a diagrammatic view showing an velectrical system particularly adapted for use with the apparatus,

Figure 1 is a side elevation of a modified form of control lever means, parts being shown in section,

Figure 8 is an edge elevation of the same, and,

Figure 9 is a detail sectional view illustrating one means to provide an adjustable connection between the lever means and one of its associated rod connections.

Referring to Figure 1, the numeral I6 designates a motor -vehicle engine shown in the present instance as being of the V-type. The engine delivers power in the usual manner through a suitable clutch` (not shown) operable by a clutch pedal II, and through a transmission controlled by a gear shift lever I2. The engine is provided with the usual intake manifold I3 to the upper end of which is connected a carbureter indicated by the numeral I4 and provided with the usual throttle y,45. through the usual throttle arm I6.

Any suitable form of power device may be employed for operating the clutch pedal Il. In the present instance such power device has been illustrated as comprising a pair of casing sections I1 having a diaphragm I8 connected therebetween and connected to a pull rod I9 extending through the rear casing section I1. The latter casing section may be vented to the atmosphere in the usual manner and a pressure diierential is established in the power device, to disengage the clutch, by establishing a partial vacuum in the forward casing section I1 through the medium of a vacuum conduit 20, in a manner to be described.

The left end of the rod is (see Figure 1i is connected as at 2| to the right end of a cable 22, and the left end of this cable is connected to the upper end of an operating arm 23. The lower end of vthe arm 23 is rigidly connected to the clutch operating shaft 24. It is preferred,

that the pedal II be freely rotatable with respect to the shaft 24 so that the latter may be operated by the powerdevice without transmitting movement to the pedal. When such form of clutch operating means is employed, the pedal I-I is provided with a lug 25 engageable with the arm 23 to operatethe clutch when the pedal II is'depressed by the foot of the operator.

As previously stated," the present invention is adapted for use in connection with the valve mechanism disclosed in the'patent to Edward G. Hill No. 1,964,693, although it is not limited to use in connection with such valve mechanism. It has been found however, that the invention to be described operates particularly eiiiciently in connection with such valve mechanism, and be cause of this fact, such valve mechanism has been illustrated in Figures 2 and 3 of the drawings. It will be understood, however, that the control valve mechanism. forms no part of the .present invention, except in combination with the control means therefor.

Referring to Figures 2 and 3, the numeral 26 designates a cylindrical valve casing in which a cylindrical valve 21 is slidable. This valve is operated by a rod 28, in a manner to be described, and a spring 29 urges the stem 28 and valve 21 to the left, as will lbe apparent. The valve 21 is provided with opposite arcuate vacuum ports 30 and 3I and an arcuate atmospheric port 32. A second valve 33-is slidable within the valve 21 and is provided intermediate its ends with a reduced portion 34 forming a port operable in a manner to be described for con- This throttle is operable` 3| and between the port 32 and the atmosphere.

The valve casing 26 is provided with a vacuum port 35 connected at its opposite end to a vacuum conduit 36, leading to the intake manifold I3, as shown in Figure 1. Communication through the port 35 is controlled by a valve 31, as shown in Figure 2. A solenoid 38 is mounted in a casing 39, preferably formed integral with the valve casing 26, and the valve 31 forms the armature of the solenoid 38. A light spring 46 tends to urge the valve 31 to closed position, and the valve 31 opens when the solenoid 38 is energized in a manner to be described.-

When the valve 21 is moved toward the right from the position shown in Figure 2, the ports 30 and 3l communicate with the cut out portion of the valve 33, thus affording communication between the port 35 and a port 42 formed in the valve casing 26 and elongated longitudinally thereof to alord constant communication with the valve porty 32. A laterally extending passage 43, also formed in the valve casing 26, is connected to one en'd of the vacuum conduit 26, previously described.

The valve casing 26 is enlarged at the end opposite the valve rod 28 to form an annular casing section 44. A second similar annular casing section 45 is arranged adjacent the casing section 44 and a diaphragm 46 is arranged between these casing sections. The diaphragm 46 is connected to the valve 33 as at 41. The casing section 45 is provided with an axial extension 48 in which is arranged a spring 49 tending to urge the valve 33 toward the left as viewed in Figure 2. Any suitable means, such as the screw means 50, may be employed for adjusting the operating tension of the spring 49.

The casing section 44 is vented to the atmosphere as at 5I, and the pressure in the casing section 45 is dependent upon the pressure in the right casing section I1 of the power device. The casing section 45 is provided with a port 52 communicating through a port 53 in the diaphragm 46 with a small conduit 54 leading to the passage 43. Since the passage 43 oommunicates with the power device and with the chamber formed between the casing section 45 and diaphragm 46, it

sure in the power device to thus determine the position of the valve 33.

The valve casing 26 carries a lateral extension i 55 yin which is formed an air chamber 56 communicating with the atmosphere through a relatively large port 51. A port 58" communicates at one end with the valve port 30 and a valve 59 engages a seat to control communication between the port 58 and chamber 56. A bleed port 6I affords communication between the port '58 and the atmosphere and the eiective area of the port g; may be adjusted by means of a suitable screw The lateral extension 55 carries an annular casing section 63 coacting with a similar casing section 64 to receive a diaphragm 65 therebetween. 'I'he inner face of the diaphragm 65 is subjected to atmospheric pressure in the chamber 56, as will be apparent. The valve 59 carries a stem 66 connected to the diaphragm 65, and movement of this diaphragm accordingly controls the valve 59. An axial extension 61 is carried by the casing section 64 and houses the outer end of a relatively light spring .68, the inner end of this spring seating against the diaphragm 65 to tend to urge the valve 5! in closed position. Suitable screw adiusting means indicated as awhole by the numeral 69 is employed for adjusting the effective tension of the spring 68. A vacuum passage 10 communicates at one end with the passage 43 and at its opposite. end with the chamber formed between the diaphragm 65 and casing section 64, the latter two elements being provided with passages or ports 1| and 12 for this purpose.

The lever operating means for the throttle and valve mechanism is shown in detail in Figures 4 and 5, and is illustrated in Figure 1 in its relationship to the other parts of the apparatus. Referring to Figures 4 and 5 the numeral 13 designates an upstanding bracket having a base portion -14 secured as at 15 to the intake manifold or any other portion of the vehicle engine. A lever 16 is pivotally connected at its lower end to the bracket 13 as at 11. lAn arm 18 is carried by or formed integral with the bracket 13 and proper alinernent for connection with the throttle nected to the lever 8|.

arm |6 and valve rod 28. For this purpose, the lever 8|-is provided with a laterally extending boss 83 and the pivot bolt 82 passes through the boss 83 and the upper end of the` lever 16. The

ally from the lever 16 and carries a stop screw 86 engageable against the lever 8| to limit the turning movement thereof in a clockwise direction around the axis of the bolt 82. secures the screw 86 in adjusted'positions.

Referring to Figure 1 the numeral 88 designates the accelerator pedal extending through the vehicle dash 89. The pedal 88 forms one end of a lever pivotally supported intermediate its ends as at 90. The other end 9| of this lever is arranged in the engine compartment, and a spring 92 urges the acceleratorA pedal upwardly and the lever arm 9| forwardly. As shown in Figure 1, a rod 93 is pivotally connected at its left end as at 94 to theupper end of the lever arm 9|, and at its right end the rod 93 carries a pivot b'olt 95 adjustable with respect to the slot 84 and adapted to be'secured in any desired position along the lever 8l.

The pivotal connection between the rod 93 and the lever 8| may be of the type illustrated in detail in Figure 9 of the drawings, The rod 93 is provided with a circular end 96, and the bolt is'provided with a shank 91 extending therethrough. 'The bolt is further provided 'with a reduced portion 98 extending through the slot 84 and provided on its free end with a nut 99. This nut may be drawn up tight against one side of the lever 8| while the shoulder at the end of the shank 91 engages the other side of this lever. Thus it will be apparent that the bolt 95 may be fixed in adjusted positions with respect to the lever 8|, while the rod 93 is free to turn about the shank 91.

vReferring to Figures 1 and 4, a rod or link |00 is pivotally connected at its left end to the lever 8| as at |0| andthe right end of the link |00 A is pivotally connected to thev throttle arm |6 as The lock nut a1 at |02. These pivotal connections may be of the type illustrated in Figure 9 to permit proper securing of the pivot members without binding the pivotal connections of the link |00.V Obviously the pivot bolt |0| may be secured in any adjusted position along the slot 84. A similar link |03 is pivotally connected at its left end (see Figures 1 and 4) to the lever 8| as at |04 and at its right end to the left end of the valve rod 28 as at |05.

In Figures 7 and 8 a somewhat modified form of lever means is illustrated. A bracket |06, coris provided with a foot portion |01 secured to any stationary part of the motor vehicle engine as at |08. A lever |09 is pivotally connected at its lower end to the bracket |06 as at ||0. A second lever is pivotally connected at its upper end as at ||2 to the upper end of the lever |09. A rod I3 is also connected at one end to the pivot member ||2 and carries a piston ||4 at its opposite end operable n a cylinder ||5. The piston I4 is provided with a relatively small port I6 therethrough, and a spring |1 urges'the piston ||4 toward the right as viewed in Figure 7. The piston |.|4 and its port |6 operate as a dash pot to tend to retard movement of the upper end of the lever to the right when the accelerator pedal is suddenly released from a depressed position, for a purpose to be described. As will become apparent, the spring ||1 is not essential, but may be provided as the return spring for the engine throttle. The right end of the cylinder ||5 is open to the atmosphere as at 8, and the cylinder l5 is pivotally supported as at ||9 to permit it to alter its position in accordance with the pivoting movement of the lever |09. The left end of the cylinder H5 (see Figure '1) may be provided with a check valve I5 to permit unrestricted movement of the piston |4 toward the right.

The lever may be shaped as shown in Figure 7 with the ends adjacent the pivot thereof sloping toward the right and downwardly with respect to the lever |09, then toward the right and substantially horizontally as at |20, and then downwardly substantially vertically as at |2|. The sloping portion of the lever is slotted as at |22 to receiveV an adjustable pivot pin |23 lwhich connects the right end of an accelerator pull rod |24 to the lever The left end of the rod or link |24 is adapted for pivotal connection as at |25 to the accelerator lever arm 9|. A similar link |26 has a pivot member |21 at its left end adjustable in a slot |28 formed in the lever |09. The right end of the link or rod |26 is pivotally connected as at |29 to the throttle arm I6.

A pivot bolt |30 is adjustably mounted ina slot |3| formed in the vertical portion |2| of the lever As shown in Figure '1 pivot member |30 connects the left end of a link |32 to the free end ,of the lever i, and the right end of the link |32 is pivotally connected as at |33 to the left end of the valve rod 28.l

A small cylinder |34 is pivotally connected as at |35 to van arm |36 carried by or formed integral with the lever |09. A piston |36 is mounted in the cylinder |34 and is provided with a small port |31 therethrough. A piston rod |38 is connected to the piston |36 and is 'pivotally connected at its right end tothe lever by the pivot member |30. A spring |39 urges the piston |36 toward the right, and an adjustable set screw Vresponding to the bracket 13 previously described, s

|49 limits the movement of the piston |36 toward 75 the left in the cylinder |34, for a purpose to be described. A small check valve |40 permits unrestricted movement of the piston |36 toward the left.

An electrical system adapted for use in. connection With the apparatus iS illustrated in Figto the ignition system (not shown) of the vehicle. The contact A|45 is also connected as at |46 to a. main control switch |41 engageable with a contact |48. The switch |41 is closed to render the clutch control mechanism operative and is opened to permit manual control of the clutch, as will become apparent. The contact |48 is connected by a wire |49 toone terminal of the solenoidv 38. In this connection it will be noted that the solenoid, in practice', is made a part of the main valve mechanism, and for the purpose of illustration the solenoid is illustrated in Figure 6 as being arranged in the conduit 36.'

The other terminal of the solenoid is connected to one end of a wire |5|l leading to a. button |5| mounted at the upper end of the gear shift lever,

- and such lever is indicated as being grounded as at |52. A branch wire |53 leads from the wire |56 to a switch arm |54 normally engaging a contact grounded as at |56. The second andhigh speed shift rod |51 of the vehicle transmission moves toward the right as viewed in Figure 6 when the gear shift lever is in high gear position to move the switch arm v|54 out of engagement with the contact |55, for a purpose to be described.

A branch wire |58 leads to` a switch arm |59 engageable with a contact |60 grounded as at |6i. Afwire |62 leads from the Wire |58 to :an arcuatev contact |63 .which may be mounted in the speedometer |64. A switch arm |65 is movable with the speedometer and engages the arcuate contact |63 at low vehicle speeds, for example, from zero speed to a predetermined maximum speed of eight to ten miles per hour. A wire |66 leads from the switch arm |65 to a ground |61. The operation of the apparatus is as follows: The operation ofthe main valve mechanism is described in detail in the prior patent of Edward G. Hill No. 1,964,693 and no specific description of such mechanism need be repeated here. In a manner to be described, the valve 21 moves to the position shown in Figure 2 when the throttle is opened to` a predetermined extent, and when the throttle is released for movement to idling position, the valve 21 moves substantially to its limit of movement toward the right as viewed in Figure 2. Movement of this valve as the accelerator pedal'is released moves the port 32 out of registration with' the reduced portion 34 of the valve 33, thus cutting oi communication between the port 42 and the air port 58 (see Figure 3) and at' the same time, the ports 30 and 3| will be moved into communication with the reduced portion 34 of the valve 33 to connect the power device |1 to the intake manifold through ports 35 and 42 and the conduit 36. Under such conditions it is pedal is depressed, the valve 21 moves to the left to disconnect the power device from the intake manifold and admit air into the power device through port 51, chamber 56, passage 58, ports 32 and 42, passage 43 and pipe 28. In this connection, it will be noted that when the power device is connected to the intake manifold to eii'ect declutching, the vacuum chamber of the casing section 64 (see Figure 3) is subjected to the reduced pressure of the power device through ports 18, 1l and 12, while the vacuum chamber within the casing section 45 (see Figure 2) is subjected to the same reduction in pressure through the ports 52, 53 and 54. Thus the valve 59 will be maintained open, while the diaphragm 46 will hold the valve 33 toward the right as viewed in Figure 2.

upon movement of the valve 33 toward the left as viewed in Figure 2 reduces the diierential pressure in the power device to release the clutch elements for movement toward operative engagement. The speed of movement of the power device diaphragm I8 incident to the pressure of the clutch springs tends to maintain a reduced pressure in the power device and in the suction chambers within the casing sections 45 and 64. In this connection it will be noted that the spring 68 is very light, and only a slight diierential pressure is necessary on opposite sides of the diaphragm 65 to hold the valve 59 open. The spring 49 is somewhat stronger, but the reduced pressure maintained in the casing section 45 during initial movement of the clutch elements upon the partial opening of the throttle is sufficient to hold the valve 33 in its position toward the right as viewed in vFigure 2. A slight increase in pressure in the casing section 45 occurs upon the initial light contacting of the clutch elements, whereupon the spring 49 effects slight movement of the valve 33 toward the left to move the reduced shank portion 34v out of registration with the port 32, thus cutting off the further admission of air into the power device. If the throttle is partially opened and its movement is then stopped, the clutch elements will remain indefinitely in a position lightly contacting with each other. Under such conditions, any tendency of the clutch elements to overrun the position indicated is prevented, since such action can occur only upon a reduction in the differential pressure in the power device which would react in the diaphragm casing section 45 to cause the valve 33 to move to a slightly greater extent toward the left thus slightly opening the ports 36 and 3| to communication with each other, thus reestablishing the proper pressure diierential in ment of the valve 33 incident to the initial engagement of the clutch elements will not operate to completely arrest movement of the clutch elements, since the valve 21 will be progressively moving as the throttleis progressively opened. Accordingly, the movement of the clutch elements will be retarded approximately at the point of initial engagementl and then will continue to move slowly into operative engagement as the throttle is progressively opened to accelerate the engine speed. l

The electrical system disclosed in Figure 6 is particularly adapted for use with the present apparatus to provide selective operation, but the When 78 use of such system is not at all essential.

the ignition switch |43 and the main control switch |41 are closed and the vehicle is in first, second or reverse gears to permit the switch |54 to remain closed, the solenoid 38 will remain energized, and accordingly operation of the clutch control mechanism is wholly dependent upon the operations of the valves 21 and 33. Accordingly, declutching will be effected at each releasing of the accelerator pedal except when in high gear and below a predetermined speed. For example, if the vehicle speed is above the speeds at which the brush |65` engages the contact |63 when the vehicle is in high gear, the solenoid 38 will be deenergized, provided the switch |59 is open and the button |5| is released, and the accelerator may be released without declutching, thus pery mitting the engine to be used as a brake.

r apparatus under such conditions cannot be affected by the position of the gear shift lever. The closing of the switch |59, therefore, provides automatic free wheeling under all conditions, whenever the accelerator is released. The button |5| is provided to permit declutching upon the releasing of the accelerator pedal when in high gear and at relatively high vehicle speeds to permit shifting into second gear without awaiting vehicle deceleration to the point at which.

the brush |65 engages the contact |63.

The foregoing description covers the operation of the main valve mechanism and the electrical system, and will render the operation of the control means for the main valve mechanism more readily understood. In most prior clutch control mechanisms of which we are aware, the initial opening movement of the throttle takes place simultaneously with the initial operation of the valve mechanism through which the clutch elements are brought into engagement. The present mechanism, under ordinary conditions, provides operation of the valve mechanism slightly prior to throttle operation, thus putting the clutch elements in a condition for operative engagement upon opening movement of the throttle. In many vehicle installations, this is unnecessary, but its use is desired with several types of vehicles in which rapid engine acceleration takes place upon opening movement of the throttle. With vehicles of the latter type the present mechanism provides clutch vengagement without the spinning of the motor and the wearing'of the clutch elements incident thereto. Moreover, the present device provides Vfar more rapid clutch disengagement with respect to throttle position, thus preventing the transmission of motor drag to the vehicle upon the release of the accelerator pedal.

Referring to Figures 1 and 4, it will be noted that the accelerator lever arm 9| is connected to the lever 8| by the link 93, and when the throttle is in idlingv position the levers 16 and 8| occupy the positions shown in Figure 4. The lever 16 is in engagement with the stop screw 19, while the lever 8| is slightly spaced from the screw 86. The initial movement of the accelerator 88 from idling position, therefore, swings the lever 8| about its pivot 82 without transmitting any movement to the lever 16 until the lever 8| contacts with the stop screw 86. The throttle connection has its pivotal connection |0| arranged much closer to the pivot 82 than the pivotal connection |04 of the link |03. Upon initial depression of the accelerator pedal therefore, the valve 21 initially moves much more rapidly than the throttle, and accordingly the clutch elements will be released for movement toward operative engagement and then checked before the throttle opens to any substantial extent. The clutch elements are then ready to move into operative engagement upon further opening movement of the throttle, and since the movement of the clutch elements to the point of initial engagement occurs very rapidly and prior to substantial motor acceleration, the motor is prevented from spinning prior to initial clutch engagement, thus preventingv any undue wearing of the clutch elements. y

The checking of the movement of the clutch elements preferably occurs at least as early as the contact between the lever 8| and stop screw 86, and the latter element Ais adjustable to permit the checking action to occur at the desired point. After engagement of the lever 8| and screw 86 takes place, further depression of the accelerator pedal causes the levers 8| and 16 to move as a unit, the latter lever pivoting on the axis of the screw 11. Such further movement accordingly takes place with the pivot of the screw |04 closer to the axis of rotation than the axis of the screw |0|, and accordingly opening movement of the throttle becomes relatively faster than movement of the valve 21. This fact permits the valve mechanism to be made shorter, since the length of movement of the valve 21 in proportion to the throttle movement is shortened over previous constructions. However, in previous devices, it has been necessary to make the valve mechanism relatively long in order to permit valve movement throughout the range of movement of the accelerator throttle. This is unnecessary in the present construction, however, as will become apparent. Full clutch engagement obviously takes place long before the throttle reaches its fully open position, and thepresent device renders it unnecessary for the valve 21 to continue its movement beyond the point where full clutch engagement has taken place. At the latter point, or

'slightly therebeyond, the valve 21 engages the left hand end of the valve cylinder 26, as shown in Figure 2, whereupon the lever 8| can no longer move as a unit with the valve 16. Further movement of the throttle toward open position by depressing the accelerator, therefore, causes the lever 16 to swing about its pivot 11, while the lever 8| swings slightly in a counter-clockwise direction about its pivot 82, the pivot |04 remaining relatively stationary. The movement of the upper end of the lever 8|, however, permits the link 93 to continue'to transmit movement to the link |00 to continue the opening movement of the throttle.

The reduced ratio of movement of the valve 21, and the fact that this valve need not move after full clutch engagement has taken place, permits a relatively short valve housing to be employed, While the relatively fast initial movement of the valve 21 permits the clutch elements to reach the check point relatively fast with respect to the movement of the throttle, thus preventing the racing of the ymotor in the manner indicated. These two features are highly desirable in connection with the operation of a clutch control mechanism.

The control mechanism also operates in a highly desirable manner upon the movement of the throttle to idling position. Assuming that mechanism to release the clutch elements form movement to the check point referred to. In

the throttle is in a fairly wide open positlon,.the lever 0| will be beyond engagement with the stop screw 86, assuming that the valve 21 has been moved to its limit of movement as shown in Figure 2, while the lever 16 will be to the left of the position shown in Figure. 4, out of engagement with the stopv screw 19. If the throttle then moves to idling position by the releasing of the accelerator pedal, the level 16 moves to the left until it contacts with the stop screw 19, the lever 8| being brought into engagement with the stop screw 86 during such movement. Afterthe movement of the lever 16'is arrested by engagement with the screw 19, the continued upward movement of the accelerator pedal causes the lever 8| to swing in a counterclockwise direction about its pivot 82, and during such movement the pivot pin |04'moves much more rapidly than the pivot pin |0|,l thus transmitting rapid movement to the valve 21-to effect declutching, while the throttle moves relatively slowly to idling position. Thus motor drag is effectively eliminated, and the device thus operates smoothly when declutching for gear shifting. It also will be apparent that smooth declutching is provided when free Wheeling, and this result has been substantially impossible with prior constructions due to the substantial deceleration of the motor prior to clutch disengagement.

It will be apparent of course that the operation of the valve mechanism per se is substantially identical with the operation disclosed in the patent to Edward G. Hill No. 1,964,693, referred to above, except that the movement of the valve 21 is coordinated with the movement of the throttle valve in an entirely different manner to provide the improved results referred to. 'I'he valve 21 moves initially relatively rapidly upon opening movement of the throttle to bring the clutch elements into initial contact prior to substantial acceleration of the vehicle engine, and thereafter moves relatively slowly while full clutch engagement takes place during substantial motor acceleration. In the event the throttle is depressed too rapidly, the rapid decrease in the differential pressure in the power device |1 is communicated to the diaphragm 65, whereupon the valve 59 closes to prevent too rapid clutch engagement. Accordingly it will be apparent that the jerking or lunging of the vehicle is effectively prevented.

The operation of the valve mechanism during declutching is also similar to the operation of the valve mechanism disclosed in the prior patent referred to. operation of the present device lies in the rapid movement of the valve 21 prio-'r to the point at which the throttle reaches idling position to provide rapid and substantial communication between the power device and the intake manifold to completely disengage the clutch prior to the point at which the throttle reaches the idling position. As previously stated, this operation prevents the transmission of motor drag to the vehicle.

The operation of the form of the device shown in Figures '1 and 8 is quite similar to the form previously described and need not be described in detail; Referring to Figure '1 it will be noted that the throttle operating link |26 is connected to the lever |09 instead of to the lever ll and the difference in this arrangement lies in the fact that no throttle movement will take place upon depression of the accelerator, under ordinary conditions, until the lever has operated thevalve The principal diierence in thev other words, insteadof relatively fast valve operation and relatively slow throttle operation at the initial depressionof the accelerator pedal, the form of the invention illustrated in Figure '1 prevents any operation of the throttle until the clutch, elements have reached the check point. The screw |40 contacts with the piston |35 to limit the movement of the lever with respect to the lever |09, and after this limit of'movement is reached, further movement of the accelerator pedal causes the levers |09 and l to turn as a unit about the axis of thel pivot screw I0.

Where fast clutch engagement is desirable, as when the gear shift lever is shifting from second to high gear position with the vehicle moving at a substantial speed, the accelerator pedal may be rapidly depressed tothe desired extent, whereupon the piston |36 and cylinder |34 function as a dash .pot to cause movement to be transmitted from the lever to the lever |09 slightly prior to the point at which the piston |36 engages the stop screw |40.- This arrangement permits rapid enginelacceleration and rapid clutch engagement, which is entirely possible under the conditions referred to, without causing anyjerking or lunging of the vehicle.

The dash pot elements ||4 and H5 may be provided to positively eiect declutching upon the sudden complete releasing of the accelerator pedali The spring |1 may be provided with an auxl tion, the partial vacuum created within the left hand end of the cylinder I5 slightly retards the movement of the lever 09, thus permittingthe lever to lead the lever |09, and thus operate the control valve mechanism to provide full communication between the power device |1 and intake manifold slightly prior'to the time at which the throttle reaches full idling position.- Thus the clutch will be released, or the pressure'of the clutch plates will be released to a. substantial extent, before the vehicle engine is able to transmit any motor drag to the vehicle.

The form of the invention shown in Figures '1 and 8 is particularly applicable to vehicles having unusually high powered motors with substantial piston displacement. Forexamp1e,amotor of such character may be unusually rapidly responsive to throttle action whereby very rapid vmotor acceleration takes place upon vopening movement of` the throttle. Moreover, a high speedmotor of substantial piston displacement may tend to cause motor drag upon the sudden releasing of the accelerator pedal, and the form of invention referred to operates to insure declutching 'sufficiently early with respect to throttle action to prevent the motor drag referred to. For most installations, the form of the invention shown in Figures 1, 4 and 5 will properly control the valve mechanism for all purposes. The valve mechanism shown in Figures .2 and 3 provides the smoothest and most accurate clutch operation of which we are aware, and while the control means for the valve mechanism is not limited in its use to the type of valve mechanism referred to, its

use has been found to be particularly advantageous with such valve mechanism since the combination of the two mechanisms provides `re markably smooth and accurate clutch operation under all conditions.

It is to be understood that the forms of the invention herewith shown and described are to be taken as preferred examples of the same and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

We claim:

1. Clutch control mechanism for a motor vehicle including an engine having a throttle and an accelerator therefor, comprising a power device connected to the clutch, and control /means operative with the throttle for effecting relatively more rapid movement of said power device in the range of movement of the throttle adjacent the idling position than in the remaining range of throttle movement.

2. Clutch control mechanism for a motor vehicle including an engine having a throttle and an accelerator therefor, comprising a power device connected `to the clutch, control means for the power device including a movable member, and means connecting said movable member to the throttle and operative for effecting relatively more rapid movement of said power device in the range of movement of the throttle adjacent the idling position than in the remaining range of throttle movement.

3. Clutch control mechanism for a motor vehicle'including a clutch and an engine having' a throttle, comprising a power device connected to the clutch, control means for said power device, and actuating means for rendering said control means operable for actuating said power device upon closing movement of the throttle and for deactuating the power device upon opening movement of the throttle, said actuating means being operative in the initial range of movement of the throttle from idling position for deactuating the power device relatively rapidly with respect to the. rate of opening movement of the throttle and then relatively more slowly with respect thereto.

4. Clutch control mechanism for a motor vehicle including la clutch and an engine having a throttle, comprising a power device connected to the clutch, control means for said power device, and actuating means for rendering said control means operable for actuating said power device f upon closing movement of the throttle and operative upon opening movement of the throttle forinitially releasing the clutch elements for movement toward operative engagement, checking the movement of the clutch elements prior to operative engagement and then releasing the clutch elements for movement into operative engagement, said actuating means being operative relatively rapidly with respect to the rate of movement of the throttle in the initial range of movement of the throttle from idling position for operating said control means to release the clutch elements for movement toward operative engagement and then check the movement of the clutch elements, and then operative relatively more slowly with respect to the rate of movement of the throttle. g

5. Clutch control mechanism for a motor vehicle including a clutch and an engine having a throttle, comprising a power device connected to the clutch,control means for said power device including a pair of relatively movable members one of which is actuated lin response to the actu- -v ing movement of the throttle and the deactuation of the power device upon opening movement of the throttle, said actuating means being operative in the initiall range of movement of the throttle from idling position for deactuating the power device relatively rapidly with .respect to the rate of opening movement of the throttle and then relatively more slowly with respect thereto.

6. Clutch control mechanism for a motor vehicle including an engine having a throttle and an accelerator therefor, comprising a power device connected to the clutch, control means for the power device including `a movable member, and actuating means connecting the throttle and said movable member to the accelerator and op- -erable for eiecting movementof such movable in the range of movement of the throttle adjacent the idling position than in the remaining range of throttle movement.

7. Clutch control mechanism for a motor vehicle including a clutch' and an engine having a throttle and an accelerator therefor, comprising a diiferential pressure power device connected to the clutch, control means for said power device including a movable valve, and actuating means connecting the throttle and said valve to the accelerator and operablefor moving said valve relatively more rapidly than the throttle in the range of movement of the throttle adjacent the idling position than in the remaining range of throttle movement.

8. Clutch control mechanism for a motor vehicle including a clutch and an engine having a throttle and an accelerator therefor, comprising a differential pressure power device connected to the clutch, control means for said power device including a pair 4of control valves one of which is movable upon movement of the power device, and actuating means connecting the throttle and said other valve to the accelerator and operative for moving said other valve relatively more rapidly in the range of movement of the throttle adjacent idling position than in the remaining range of throttle movement.

9. Clutch control mechanism for a motor vehicle including a clutch and an engine having a throttle and an accelerator therefor, comprising l a differential pressure power device connected to the clutch, control means for saidlpower device including a movable valve, andactuating means connecting the throttle and said valve to the accelerator and including lever means operable for moving said valve relatively more rapidly in the range of movement of the throttle adjacent the idling position than in the remaining range of throttle movement.

10. Clutch control mechanism for motor vehicles including a clutch and an engine having a throttle and an accelerator therefor, comprising a differential pressure power device connected to.

idling position than in the remaining range of throttle movement.

11. Clutch control mechanism for a motor vehicle including a clutch and an engine having a throttle and an accelerator therefor, comprising a differential pressure power device connected to the clutch, control means for said power device including a movable valve, lever means connecting the throttle and said valve to the accelerator, and means forchanging the eiective lever lengths 4of said lever means for eiiecting movement of said valve relatively more rapidly in the range of movementof the throttle adjacent the idling position than in the remaining range of throttle movement.

12. Clutch control mechanism for a motor ve.

hicle including a clutch and an engine having a throttle and an accelerator therefor, comprising a diiferential pressure power device connect-A ed to the clutch, control means for said power device including a pair of cooperating relatively movable control valves one of which is -movable upon movement of the power device, lever means connecting the throttle and said other valve to the accelerator, and means for changing the effective lever lengths of said lever means for moving said other valve relatively more rapidly in therange of movement of the throttle :adjacent idling position than .in` the remaining range of throttle movement.

13. Clutch control mechanism for a motor vehicle including a clutch and an engine having a throttle and an :acceleratorA therefor, comprising a diierential pressure power device connected to the clutch, control means for said power device l including a movable valve, a pair of levers pivotally connected to each other adjacent one end, means for-pivotally supporting one lever adja- Icent its other end, means connecting the other lever to the accelerator, means connecting one lever to said valve, means connecting one lever to said throttle, and means operative upon movement of the accelerator for altering the operation of said levers for moving said valve relatively more rapidly in the range of movement of the throttle adjacent the idling position than in the remaining range of throttle movement.

I4. Clutch control mechanism for a motor vehicle lincluding a clutch and an engine having a throttle and an accelerator therefor,y comprising a diierential pressure power device connected to the clutch, control means for said power device including a movable valve, a pair of levers pivotally connected to each other adjacent one end, means for pivotally supporting one lever adjacent its other end, means for connecting one of -said levers to said accelerator, a connection between the throttle and one lever, a connection between said valve and one lever, said rst named connection being closer to the pivotal connection between said levers than said second named connection, and means for preventing turning movement oi said levers with respect to each other except in the initial range of movement of the accelerator.

l5. Clutch control mechanism for a motor vehicle including a clutch and an engine having connection, and means for limiting the turning 5 movement of said other lever with respect to the rst named lever as the accelerator is depressed to open the throttle from idling position.

16. Clutch control mechanism for a motor vehicle including an engine having a throttle and l0 an accelerator therefor, comprising a power device connected to the clutch, control means forv the power device including a, movable member,Q and actuating means connecting the throttle and said movable member to the accelerator and opl5 erable for eiecting movement of such movable member relatively more rapidly than the throttle in the range of movement of the throttle adjacent the idling position than in the remaining range of throttle movement when the ac- 20 celerator is operated at a speed less than a predetermined speed, and means for causing said actuating means to open the throttle relatively more rapidly in the range of movement adjacent the idling position when the accelerator is op- 25 erated at a rate of speed greater than said predetermined speed. I

17. Clutch control mechanism for a motor-vehicle including a clutch and an engine having a throttle and an accelerator therefor, compris- 30 ing a diierential pressure power device connected to the clutch, control means for said power device including a movable valve, and actuating means connecting the throttle and said valve to the accelerator and operable for moving said 35 valve relatively more rapidly than the throttle in the range of movement of the throttle adjacent the idling position than in the remaining range of throttle movement when the accelerator is operated at a speed less than a predeterlil) mined speed, and means for causing said actuating means to open the throttle relatively more rapidly in the range of movement adjacent the idling position when the accelerator is operated at a rate of speed greater than said predeter- 45 mined speed.

18. Clutch control mechanism for a motor vehicle including an engine having a throttle and an accelerator therefor, comprising a power de'- vice connected to the clutch, control means for 5o the power device including a movable member, actuating means connecting the-throttle and said movable member to the accelerator and operable for effecting movement of such movable member relatively more rapidly than the throttle in the 55 range of movement of the throttle adjacent the idling position than in the remaining range of throttle movement, and means for retarding closing movement of the throttle with respect to said movable member in the range of movement 60 adjacent the idling position when the accelerator is released for movement at a speed greater than a predetermined speed. A

19. Clutch control mechanism for a motor vehicle including a clutch and an engine having 65 a throttle and an accelerator therefor, comprising a differential pressure power device connected to the clutch, control means for said power y device includinga movable valve, actuating means connecting the throttle and said valve to the 70 accelerator and operable for moving said valve relatively more rapidly than the throttle in the range of movement of the throttle adjacent the idling position than i'n the remaining range of throttle movement, and means for retarding 75 movable member to the accelerator and operable for eiecting movement of such movable member relatively more rapidlyl than the throttle in the range of movement of the throttle adjacent the idling position than in the remaining range of throttle movement, means for causing said actuating means to open the throttle relatively more rapidly in the range of movement adjacent the idling position when the acclerator is operatedat a rate of speed greater than a pre--l determined speed, and means for retardlng closing movement of the throttle with respect to said movable member in the range of movement ad,-

:jacent the idling positionfwhen the accelerator is released for movement at a speed greater than a predetermined speed.

21. Clutch control mechanism for a motor vehicle including a clutch and an engine having a'throttle and an accelerator therefor, comprising a differential pressure power device connected to the clutch, control means for said power 1device including a movable valve, actuating means connecting the throttle and said valve to the accelerator and operable for moving said valve relatively more rapidly than the throttle in the range of movement of the throttle adjacent the idling position than in the remaining range of throttle movement, means causing said actuating means to open the throttle relatively more'rapid.

ly in the range of movement adjacent the idling position when the accelerator is operated at a rate of speed greater than a predetermined speed, and means for retarding movement of the throtltle with respect to said valve toward closed position in the range of movement adjacent idling position when the accelerator is released for movement at a speed greater than a predetermined speed.

22. Actuating means for a motor vehicle clutch control mechanism comprising a lever pivotally supported'adjacent one end, a second lever pivotally connected at one end to the other end of said rst named lever, an engine throttle connection connected to one lever, a connection for the clutch controlmechanism connected to one lever, an engine accelerator connection connected at one end to said second named lever, and means for limiting the turning movement of said second named lever with respect to said iirst named lever.

23. In a motor vehicle having a throttle and an accelerator connected'thereto, a clutch, and control mechanism for the clutch, actuating means for theclutch control mechanism comprising 'a lever pivotally supported adjacent one end, a. second lever pivotally connected at one end to the other end'lof said rst named lever,

I a pair of \connections connected to said second named lever and adapted for'connection respectively with the vehicle engine throttle and the 

